SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b7721830baa42a1180df13050efdf2cdf6b0ab98d9c255dca4cb3d7abd8a53a1' 
  AND token = 'Of5SYRn6V/m0qStl0F+WWf2cXM68dca8BZldyWeKM0I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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