SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bdef88501ea3f8223df844aeb7cd4042ced68784a42bc38fefa409c6c62b12a9' 
  AND token = 'ez00QtpyBK30KjWObBXELbPimmUfMrSu9AP5iyIbnQk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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