SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '138554d5eeb1713ef4a8318264a40c328ff098338bd6947ea8ef91d81c8c6aea' 
  AND token = 'Lkzym669D1P9/JNzAtJHCc2E2wXBIKJqBCAVOiUAiAs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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