SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2aa8648128ab806caf2b799aa6df46298b3f8f24ce0cf02f9b659106822c831a' 
  AND token = 'Aqtr1PvdPrcO+GrDo67K+L3g3YaDbRkdExi1UETaFbw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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