SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3097cefe58a6838ed89215f744b66f3a9036f22ba80b232e00f91e518764b12' 
  AND token = 'usOKliqIw98SYpPPgi4E7BDwQsC1z26HdjpPvj1ZP5c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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