SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e483070dfd34ebabd5d2d501276ed8c9367a953dfc5b1c79246c22de5c23e755' 
  AND token = 'cf0B+j6ETiUJfaZDCGT+4zmoN/nfUZo2sTbL176hFmM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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