SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fec30712fb9421dd33ee801b373b3db30d73f7778793cc50f92df525296666f7' 
  AND token = 'tbG/xBvDpH5Ib54GYBni+Lrseq11QD4lsuVN2o0A+Sw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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