SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38b7b102dfcba5d08dcc718c580c682213f65e816f9ffc3c374716bc019108f3' 
  AND token = 'WIO/Hot367A/Q/SzkyeaCUNf97lFmExJruKNzb4CWcQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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