SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a680d54d988866fd8b8aa284cf393b83b56d7e43c16bd178dab45eb58b70f829' 
  AND token = 'bG6c4KYIGQgG0aGyQYmfRoH/Hgd3xxdWSS4kryUbkcw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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