SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0379c1eeda886f18f2113da973ab6ad45da2aad2cc41759efc5176a13c57ad3' 
  AND token = 'YtBRZLpe+yLIY7JVxzsvrhRK+pEixQ3lKRrxCtYzwPY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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