SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd026ac863bb5264bbacddac6276e2e6df15f663dddc51561d466790a90c80e70' 
  AND token = 'idzHJLtvaVXQ6yhzWzBCjMEIohIAp73byKbC9UiyTM0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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