SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb2ecab8f52334fa616dc6e93d39ab54f51b5914e4907530b00aad280e730cb4' 
  AND token = 'PCYfVQvMjfcxeRPG3uPbKNWopV7m7Hw9EJri2pMcanc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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