SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bc146ebc308227c6e09e9c8a7da632cb5490b21ce65a1c620dde7e8d3c7f0c40' 
  AND token = 'qxKl4vn2l70LrKtYOvl6iZQAVgqXHYN2O1y5oxDCeKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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