SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e911d696954a3f8422d8513835d985ce1741e1f392c3d7b45f2460f418ddb3df' 
  AND token = 'mqjZkqgHpIywTJL3aCrGqrFWJ3a/zzPggL7wivWGInE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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