SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7577abfbdae06c2eedc666c74c4cdf525faa9ac7caa770ff10c764299786cc2' 
  AND token = '875PFXck0yldlMvOdnfviwbumO4L4UV7pD6mRKppOFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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