SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '280ce4108c40c4e3a93caf07fd6416c24dd39861cdffa6bd268167a4243d7bd9' 
  AND token = 'CBhqwJ4xPMBVeARoE6dhw1WsDIMFS1aKzqTqi1kYQGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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