SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '704a3dde491ccca0322a570bc5195343db7702caedb0bad3b7c796e340a5c62d' 
  AND token = 'CAXLgNKLmkDkyOeAvfOWeKDdCXYkRpFGPud/eaDAKaU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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