SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd5103840ab9fb0de8219d27dd4435b41fc080a611876b1903c4b1cfcd479849' 
  AND token = 'XpyCqFoz2oemGoXu+VyFgFVBCTUAkhfgj19RrEk59uU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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