SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5837462df76a5806b492e3fa39a265aa6d4a9a04a5cdacd35964ee58da56221d' 
  AND token = 'ZVG+iYhxp74XfMpdgv31zKuEm6TC2BOFTmXqJSOSGRo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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