SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7fe715d2b7c4ecd3caf472e6d8a81522789f57c80b8813687c398f150ef99ad' 
  AND token = 'S5Vm0C8vqEOewR5KzBc/jVSuRx0gfXbChpylaFmymUA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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