SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fcab44275f2842ed38d3324d454c4b8655030b18a1b26fcb1bc90ec2c7667cb8' 
  AND token = 'K53Kd9ucayh4kRpSXfmQ1Y+H7+eTfvoz5j6pg9JUZvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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