SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e32452efa811c30e583da606ed886c0b5f6fa82aa7224a3581968596a486412c' 
  AND token = 'l5qXb+fb8b9IHbaKpSbdLPv/cSR0fxw2SKBLWSRcV1M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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