SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b53306903c9921fd5d6f922ac7b6b229e67cdc6464ba62aebbe495e9b096068c' 
  AND token = 'q31m9PM0NEtFS06bVryBl7sNCeOp41chFHE0PzZiLOc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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