SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b010a228263cf4070faa419113b396bde4b2ad6b597aae19ca4943c8d704696' 
  AND token = '24T3SJCmdjnx36zlgwtQ92t3fgeguMvfu2CAbPRycRg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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