SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d4e4ef91ceb11af130d5c36a81b6fa2134051f559905ea8e47b3975ba13fe37' 
  AND token = 'BZu2yR1aUuSmoq3ohnvZBlQVshmTHNWsKyZWqNfKTbo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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