SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '90b88d2850bd66e3d311dd7af69788302b7def78823c527cf3acfdfed88c8b87' 
  AND token = 'YE25m4gRuYj3L6A03Xa6kIJecXGBePu7alrk7/za8CE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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