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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4f4485a4d910747c5fc26e7b11f62e08f2fdac7d5ccaef74cc40ee4174f562f' 
  AND token = 'NG3QkB5xKZUwcSY9TCD3ne5l/5FK/9RBN92ta2gOWOU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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