SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '76d50dca23fa7c537ceb6080a48b4f5e995afbcefd1c368529c67d9e6548e809' 
  AND token = 'OiZ5YnktZwiY3wKhRgFSUje9Zvxo+gwKM0F+/BU22QY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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