SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b7a8eeb9d544674b6a4dcd25b96480e52c39ac678ca88db05fdf45fa9601f33' 
  AND token = 'N176hF2p9ql5eb822ABZfXfqxODLv+yFEHcpG9EBLR8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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