SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11e2145e3c860be5d7de193e78912051f88b85457ea66363a4b808559f74701a' 
  AND token = 'JzkhsmGxi3YlnAGKKxFzVmwMYDYL55+rg8W6X7xbnnY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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