SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2a95ca0763997469091bd24daa4ac1c9eec1310593ccc44431c8d5d683acd95' 
  AND token = 'lRqayiP9jXXItM0/gLRnJ+BSXwVAaHwiFoiQyFyZ1us=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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