SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef95f7d5a9409cd55f6f2c43db22faf199d4075624be0bd6e53d425a7197ea7d' 
  AND token = 'YE4uCS+QVIcROXaBuWnl5ZligQY0tYjUhwijvsqB4Rk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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