SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5dd10dd2d0169dad33f719ea2303094fae633307e87ba211faac92c227c9d4da' 
  AND token = 'i/NgD73UMrHxt9jm5Iv4IJupQYouadDFDVgyomI4a7c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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