SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c4f58d7f866d71f304486f8f56fe89bc73203650a05057d615de8d5717ed97c' 
  AND token = 'h64zHelD+2oeJ2zlcURDs1tk9gqj9mMsPOfMDavJ9u4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}