SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1aceaadf1c1fde3706a8db43470b5782fe390b6cd49e572a9c6b792c23e4ddbb' 
  AND token = 'MUXGo/bzVsGNk1QfkKv4DGLqYVhAMFtkjPV0n+QoVKw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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