SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b62377e0df5a69ea8002e8d07afd6b0e1c63ed844858a44032fa6071515a0663' 
  AND token = '7KyYk+rWvt+6m+ldfo96Zno07YenMFh8fN2C09C5xYQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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