SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67a186de274e4741134b9d2e7736db410ac6b53cb3e84c1d919ea77c9b600190' 
  AND token = 'FZxDdSX8jVwD2/TZlgm7tXrn+c1jAwFsyttcgFrMlz4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}