SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee30695d76dca57889d37b383df68f13ae91b154137cfbb65e316c078f6aa8fb' 
  AND token = '6w0UmFb3xvcgKyLNzZhDZsUKzY3OPjRQJs+EN2bi/os=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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