SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12347413baf6fc6b47fbf98b5b874df213c8ce84ca0b90ca2081ebb0aa604844' 
  AND token = 'BuzjJOtT63JvxtRRz089cZGRLchzMO4eqGLhIULtHR0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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