SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b2627060cf883edc30e82e863e0c51e2af976e3e7c8959db579a94ff87d7dac2' 
  AND token = 'BE+665hgQRoj122fKG/pMY2SpjhMPzy433OJMOCno/Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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