SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7bc91d93fd7c5193dc6ba3f538578a76f30be7287c3c8a96d311e2d27026a437' 
  AND token = '6+QS/gGwkLvkFdaua7vAsz3JM2AFPx4G1PBMp7UOcpg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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