SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6fd8bee88cc8d84e097bcd5222d12235653232612c929a9afff177b8a8860517' 
  AND token = 'RnQpfMwJov/YX3Cqn7o9IRH2wGgt7fHkEBvZf2RqEes=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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