SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd530177dce66e8bcce911e7961aacdcd7386d81670b21723b8a438ea8ca885bb' 
  AND token = 'b7iFEnWQtw7aMaHGRXpErRdpEiMFXPtpyM26cN5ThLI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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