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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a9724622512d18d9ccb80cb06bec68669ba71c01b687a1b6d635d6d4d02b5a7' 
  AND token = 'C/zoVBhQxDPmtEcp67fWNa1bItvZJzLjaUWFmTo/XJ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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