SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fc2377fe21224b918937d177cd0af74f0c54e82761274fded0c7f9abe00865b4' 
  AND token = 'aBsOQ4GFdCsOcGL5uFBvVKxjjrCAtt+G3WiOh88FJg4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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