SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a74d4f6d78273f8552b1df66b1b9466f085bd7411397c3f720a3e22f024355d' 
  AND token = '2LDdhFIUqqXkW2i2s0hj9QRFNAMup5rqvcUaZvci3qk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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