SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1994af593c056b14da4b4fa90bd77c280380529d4e84325e65c79fb8e5b23fa' 
  AND token = 'M0zPihA9AGS89riCKeGtTfYH+KVqq9JWuwUyNjoYr58=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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