SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb8895ca5bab3b50871067c419d1e2b408355c1e691e65c1b0361adcc31e34d2' 
  AND token = 'DuPjdaqiWmjWYEeCwrf8fscOE/VUVOkD5HX6MtXUfE0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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