SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '950e305a182758ff6b43e29e1f078735cc00d39a3b2ece3575077921edeacd38' 
  AND token = 'zYzZjvMErcyFaq4BLUY/eZBjXbgHaGsfci93nWg4MWg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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