SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85aa02842dca36f13231325719cd307429480ee36f3e1886dce373e594f9d1c1' 
  AND token = 'MhiA9bum6tBm/kkKhi8UScran94KV6ur9zMhyLtScNM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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