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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd503b60d64fb1f873ca0347394bb4859f1f05213d993a808997e8ce031a0609c' 
  AND token = 'wHs9M2DPzLabhT+dLSocZbyPDHIjczrXklira3+fPLI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}