SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3dc2163f3fcc449b1402b483c5bfe8b6e2cac45db558530016d0f190ede5c073' 
  AND token = 'Zp+sR2hj8xao4RSxAOyYIMX2RKVu0+QsuDnbz46OgDU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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