SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3078d529a79bceb70a0c8d4a420ae0d479197699395a33d6f177a37833adfb7a' 
  AND token = '1iyrcIKKD+9sRppM8XzM6cKNtXWWWTLeIcMga8+dpv4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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