SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80a5078002945ef65d86f3b5ea1095efe71d0a9d159692f7e93c20e7fc540d0b' 
  AND token = 'sFkYbuRY+6s2nlDFhQUgJISmmmECNBYYTSOyhkvGmEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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