SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fa3fb97be6c2caa4532843dd0045101f8c5a583140016217ddf91d66aaa6dc7' 
  AND token = '40cMWvdt+tXzvQlBa527mB3INaAnCRt9uybWGumA84M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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