SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cdacd80f48a851bc0b741642773e14a0f817b90ee6b6bfd921d605926eb73b1' 
  AND token = 'uEneE2+GiljCNyXWfiS3680fbpEcXqlvQTxA121fd+E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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