SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '931827c1a3bf653952a60acb2f6fad813de322b630859d33c9def1d242e9957b' 
  AND token = 'MpzErlEzLNGaDt7n72h2jtBeEV//JHOvpgsZgo6hfGA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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