SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0710c5f6892b825437d0aecf608c6c5bd1eb85ed46bafde241b1459594614762' 
  AND token = 'gxuHB/RpzCKgsn6Jn4iRBX2rtcNpvfh0zN3CqjRyTZg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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