SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cce02a2bf426cfe2b10a1bd932b0ca113ec9376f119a747a48840f400a435bbf' 
  AND token = 'Nx/8DsAfQPNcXsMsUeMxHPUQ+f3iYh4R/MEjs85fLUA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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