SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d6273366f90929541589f1f496189dc07981cd9ac4553fbe72681300dd2ceb0' 
  AND token = 'eaVFT2R2kLFYq32twOgRslrkYvZTvJmAXIQ8ZjYgMy0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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