SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e970b00359069347ce50e83001f61cdcc0f8be31bc329d433b4f672481b351d0' 
  AND token = 'dZnyx3WIklh1tFM6HO+12Hf/57uapAF0YYFbMFhqpdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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