SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b72d1e2714b8ebdf9ca64616aeaf346ecbaeadb4dc42556486322efe40dd510' 
  AND token = 'WWCubOJAbIkVchTAU9gMhqDVMQNiygqBebnixoz5rsM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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